The invention relates to a dilatation catheter having a tube the operative end of which opens into an expandable balloon and a segment of flexible tubing traversing the balloon, sealingly connected to the distal end of the balloon, and capable of being threaded by a guide wire.
Such a dilatation catheter is described in The American Journal of Cardiology, Vol. 49, Apr. 1, 1982, pages 1216 to 1222, and is employed to enlarge constrictions in vessels and body cavities, in particular coronary arteries. At the tip of such a dilatation catheter, an inflatable balloon is disposed, capable of being filled or emptied by way of a lumen inside the catheter.
In the known dilatation catheter, a tube is provided that passes over into a balloon at its anterior end. Through the interior of the balloon and the tube, in the known dilatation catheter, a flexible tube extends, projecting beyond the anterior end of the balloon and sealingly connected to the anterior end of the balloon. Through the inside of the flexible tube, a guide wire is passed, capable of being displaced relative to the balloon during the operation, so that the dilatation catheter can be advanced or retracted along the guide wire. When replacing a dilatation catheter applied with the aid of a guide catheter, it is necessary that the guide wire protrude from the patient's body by a length greater than the length of the dilatation catheter with tube. For this reason, manipulation of the known dilatation catheter is difficult, especially since the forces of friction between the guide wire and the flexible tubing passing all the way through the balloon and the tube are great.